This invention relates to an electrooptical oximeter sensor probe. More particularly, this invention relates to a sensor probe with rigid but malleable attachment means for attachment to a central site such as the tongue, gum, cheek or lip, to provide accurate readings for patients with poor peripheral circulation.
Oximeters which measure blood oxygenation levels and pulse by transilluminating blood-perfused tissue and measuring the light extinction at different wavelengths are known. One type of sensor or probe which can be used with such an oximeter is described in commonly-assigned U.S. Pat. No. 4,685,464 issued Aug. 11, 1987. Another suitable sensor conforms to and with the cutaneous layer of the blood perfused portion of flesh upon which the sensor is placed, preferably a fingertip. A light source is mounted to the first end portion of a single substrate and a photosensor is mounted to the second end portion. The single flexible substrate may be elongated, and it may be provided with adhesive. The sensor is suitably windowed so that light is allowed to take an optical path through the finger.
Although these sensors perform well under most conditions, it has been found that because they are usually attached to peripheral areas of a patient, they may yield inaccurate or no readings for patients with poor circulation. This is particularly so in cases of shock or hypothermia (whether intentionally induced or otherwise), or other conditions of lowered or inconsistent circulation. Thus, it would be desirable to provide a sensor which would yield more precise pulse and oxygen saturation readings for those patients whose lowered or inconsistent circulation produces inaccurate readings in sensors located at peripheral sites.